Interventions during pregnancy to reduce excessive gestational weight gain: a systematic review assessing current clinical evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system

Background Excessive weight gain during pregnancy is common in developed countries and increases the risk of complications during pregnancy, delivery and the postpartum period, which can affect both maternal and fetal outcome. Interventions to reduce excessive gestational weight gain have previously not been systematically evaluated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Objectives To determine whether published trials of interventions to reduce excessive gestational weight gain are of sufficient quality and provide sufficient data to enable evidence-based recommendations to be developed for clinical practice in antenatal care. Search strategy A literature search was conducted in the scientific databases PubMed, Cochrane Library, Cinhal and Pedro, and the reference lists of relevant articles were reviewed. The literature search was concluded on 15 August 2009. Selection criteria All randomised controlled trials (RCTs) were considered for inclusion. As the number of published RCTs was limited, we also considered for inclusion all nonrandomised intervention studies that included a control group. Systematic reviews were examined to identify additional original studies. Data collection and analysis Two reviewers independently assessed the quality of the methods and results of all included articles. Extracted data were classified using the GRADE system. Main results Four intervention studies with a randomised controlled design and four intervention trials with a nonrandomised controlled design met the inclusion criteria. As a consequence of important limitations in study design, inconsistency and lack of directness, the overall quality of evidence was judged to be very low using the GRADE system. Authors' conclusions The results of published intervention trials are of insufficient quality to enable evidence-based recommendations to be developed for clinical practice in antenatal care.